Zobrazeno 1 - 10
of 1 697
pro vyhledávání: '"Giallongo, E."'
Autor:
Grazian, A., Boutsia, K., Giallongo, E., Cristiani, S., Fontanot, F., Bischetti, M., Bongiorno, A., Calderone, G., Cupani, G., D'Odorico, V., Feruglio, C., Fiore, F., Guarneri, F., Porru, M., Saccheo, I.
One of the key open questions in Cosmology is the nature of the sources that completed the cosmological hydrogen Reionization at z~5.2. High-z primeval galaxies have been long considered the main drivers for Reionization, with a minor role played by
Externí odkaz:
http://arxiv.org/abs/2307.12421
Autor:
Zappacosta, L., Piconcelli, E., Fiore, F., Saccheo, I., Valiante, R., Vignali, C., Vito, F., Volonteri, M., Bischetti, M., Comastri, A., Done, C., Elvis, M., Giallongo, E., La Franca, F., Lanzuisi, G., Laurenti, M., Miniutti, G., Bongiorno, A., Brusa, M., Civano, F., Carniani, S., D'Odorico, V., Feruglio, C., Gallerani, S., Gilli, R., Grazian, A., Guainazzi, M., Marinucci, A., Menci, N., Middei, R., Nicastro, F., Puccetti, S., Tombesi, F., Tortosa, A., Testa, V., Vietri, G., Cristiani, S., Haardt, F., Maiolino, R., Schneider, R., Tripodi, R., Vallini, L., Vanzella, E.
Publikováno v:
A&A 678, A201 (2023)
The existence of luminous quasars (QSO) at the Epoch of Reionization (EoR; i.e. z>6) powered by supermassive black holes (SMBH) with masses $\gtrsim10^9~M_\odot$ challenges models of early SMBH formation. To shed light on the nature of these sources
Externí odkaz:
http://arxiv.org/abs/2305.02347
Autor:
Castellano, M., Pentericci, L., Cupani, G., Curtis-Lake, E., Vanzella, E., Amorín, R., Belfiori, D., Calabrò, A., Carniani, S., Charlot, S., Chevallard, J., Dayal, P., Dickinson, M., Ferrara, A., Fontana, A., Giallongo, E., Hutter, A., Merlin, E., Paris, D., Santini, P.
Publikováno v:
A&A 662, A115 (2022)
We investigate the ionizing properties of the pair of bright Ly$\alpha$ emitting galaxies BDF521 and BDF2195 at z=7.012 in order to constrain their contribution to the formation of the BDF "reionized bubble". We obtain constraints on UV emission line
Externí odkaz:
http://arxiv.org/abs/2203.04976
Autor:
Grazian, A., Giallongo, E., Boutsia, K., Calderone, G., Cristiani, S., Cupani, G., Fontanot, F., Guarneri, F., Ozdalkiran, Y.
Motivated by evidences favoring a rapid and late hydrogen reionization process completing at z~5.2-5.5 and mainly driven by rare and luminous sources, we have reassessed the estimate of the space density of ultra-luminous QSOs at z~5 in the framework
Externí odkaz:
http://arxiv.org/abs/2110.13736
Autor:
Boutsia, K., Grazian, A., Fontanot, F., Giallongo, E., Menci, N., Calderone, G., Cristiani, S., D'Odorico, V., Cupani, G., Guarneri, F., Omizzolo, A.
Based on results by recent surveys, the number of bright quasars at redshifts z>3 is being constantly revised upwards. Current consensus is that at bright magnitudes ($M_{1450}\le -27$) the number densities of such sources could have been underestima
Externí odkaz:
http://arxiv.org/abs/2103.10446
Autor:
Boutsia, K., Grazian, A., Calderone, G., Cristiani, S., Cupani, G., Guarneri, F., Fontanot, F., Amorin, R., D'Odorico, V., Giallongo, E., Salvato, M., Omizzolo, A., Romano, M., Menci, N.
We present the results of the spectroscopic follow up of the QUBRICS survey. The selection method is based on a machine learning approach applied to photometric catalogs, covering an area of $\sim$ 12,400 deg$^2$ in the Southern Hemisphere. The spect
Externí odkaz:
http://arxiv.org/abs/2008.03865
Constraints on Dynamical Dark Energy Models from the Abundance of Massive Galaxies at High Redshifts
Autor:
Menci, N., Grazian, A., Castellano, M., Santini, P., Giallongo, E., Lamastra, A., Fortuni, F., Fontana, A., Merlin, E., Wang, T., Elbaz, D., Sanchez, N. G.
We compare the maximal abundance of massive systems predicted in different dynamical dark energy (DDE) models at high redshifts z = 4-7 with the measured abundance of the most massive galaxies observed to be already in place at such redshifts. The ai
Externí odkaz:
http://arxiv.org/abs/2007.12453
Autor:
Grazian, A., Giallongo, E., Fiore, F., Boutsia, K., Civano, F., Cristiani, S., Cupani, G., Dickinson, M., Fontanot, F., Menci, N., Romano, M.
It is a widespread opinion that hydrogen reionization is mainly driven by primeval star-forming galaxies, with a minor role of high-z active galactic nuclei. Recent observations, however, challenge this notion, indicating a number of issues related t
Externí odkaz:
http://arxiv.org/abs/2006.02451
Autor:
Romano, M., Grazian, A., Giallongo, E., Cristiani, S., Fontanot, F., Boutsia, K., Fiore, F., Menci, N.
Publikováno v:
A&A 632, A45 (2019)
One of the major challenges in observational cosmology is related to the redshift evolution of the average hydrogen ionization in the Universe. In order to probe the ionization level of the IGM and the ionization capabilities of bright QSOs at z=4, w
Externí odkaz:
http://arxiv.org/abs/1910.02775
Autor:
Giallongo, E., Grazian, A., Fiore, F., Kodra, D., Urrutia, T., Castellano, M., Cristiani, S., Dickinson, M., Fontana, A., Menci, N., Pentericci, L., Boutsia, K., Newman, J. A., Puccetti, S.
The study of the space density of bright AGNs at $z>4$ has been subject to extensive effort given its importance for the estimate of the cosmological ionizing emissivity and growth of supermassive black holes. In this context we have recently derived
Externí odkaz:
http://arxiv.org/abs/1909.00702